Businessman Donald Trump touted his Second Amendment chops at a rally in New Hampshire on Tuesday by panning President Obama’s latest push to tighten the nation’s gun-control laws.

Mr. Trump said the executive orders Mr. Obama issued earlier in the day were “no good” and “no fair,” and made him miss the days in which presidents and members of Congress worked together to change federal laws.

“They are not going to screw around with the Second Amendment,” Mr. Trump said. “It is not going to happen. That is the way it is.”

The remarks were a direct response to the emotional plea Mr. Obama made for tighter gun control laws, announcing executive orders that would expand background checks on gun sales.

Mr. Trump is leading polls in New Hampshire, and is running second in Iowa to Sen. Ted Cruz of Texas.